简介：Understandingtheeffectsoforganicacids（OA）onthetransformationofFeandMntosurfacewaterfromtheweatheringcoalgangueisofgreatbene?ttoriskassessmentandremediationstrategiesforcontaminatedwaterandsoil.BasedontheinvestigationonsurfacewaterinthecentralcoaldistrictsoftheGuizhouProvince,18watersampleswerecollectedforheavymetalanalysis.TheresultsindicatedthatthepHvalueofsurfacewaterislow（3.11–4.92）,andFeconcentration(1.31–5.55mgL-1)andMnconcentration(1.90–5.71mgL-1)were,onaverage,10.86and34.33timesthelimitofSurfaceWaterQualityStandards,respectively.InordertoevaluatetheeffectsoftheOAonthedissolutionofFeandMnfromtheweatheringcoalgangue,columnelutionandbatchleachingexperimentswereconducted.Theresultsshowthatthelowmolecularweightoforganicacids（LMWOAs,i.e.,oxalic,tartaric,malicandcitricacids）andfulvicacidssigni?-cantlyacceleratedthedissolutionofFeandMn;inaddition,whentheconcentrationofOAreached25mmolL-1,theconcentrationsofFe,andMnwere1.14–67.08and1.11–2.32timesashighasthosein0.5mmolL-1OA,respectively.Furthermore,themigrationofFeandMnwassigni?cantlyin?uencedbythepHandEh,especiallyforFe;theionMnwasdissolvedfromtheganguemoreeasilythantheionFeinthecolumnleaching,whichwascontrarytotheresultsofbatchleaching.

简介：ThestrongadaptabilityofBroussonetiapapyrifera(L.)Vent.tolowphosphorus(P)conditionscanbeattributedtothelargeamountofroot-exudedorganicacidsandthehighef?ciencyofPextraction.However,microelementcontentsarein?uencedbylow-Pstress,andtheireffectsonthephotosyntheticcapabilityofB.papyriferaremainunknown.Inthisstudy,weinvestigatedtheeffectsoflow-Ptreatmentonnetphotosyntheticrate(P_N);chlorophylla?uorescence(ChlF)characteristics;andFe,Mn,Cu,andZncontentsofB.papyriferaandMorusalbaL.seedlings.ResultsshowthatB.papyriferaexhibitedbetterphotosyntheticcapabilityundermoderatePde?-ciency(0.125,0.063,and0.031mmol/LPtreatments),whereasthephotosyntheticcapabilityofM.albadecreasedundermoderateandseverePde?ciency(0.016and0mmol/LPtreatments).UndermoderatePde?ciency,thedecreaseinCuandZncontentsinB.papyriferawaslowerthanthatinM.alba.UnderseverePde?ciency,aconsiderabledecreaseofphotosyntheticcapabilityinB.papyriferaandM.albawasassociatedwithlowCuandZncontents.ThePNofthetwoMoraceaespeciesexhibitedabettercorrelationwithCuandZncontentsthanwithFeorMncontent.Pde?ciencycouldnotonlydecreasecyclicphotophorylationandphotosyntheticef?ciency,butcouldalsoaffectthestabilityofthylakoidmembranestructureandelectrontransportef?ciencybyin?uencingthecontentsofCuorZn,therebyaffectingphotosynthesis.

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简介：TheanalysesoflighthydrocarbonsinoilsfromtheTarimBasinshowthattheMango'sparameterKisaboutunityexceptthoseoilstrappedintheeasternpartoftheTazhong(CentralTarim)FaultUplift,TheregularvarianceofKmayindicatestheaccumulationandadmixtureoftheoilpopulationsintheeasternpartoftheTazhongFaultUplift.

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简介：ApotassiumsolubilizingbacterialstraindesignatedEGT,whichistolerantofhightemperature,wasisolatedfromanearthworm’sguttoobtainabacteriumthatcanweatherpotassium-bearingrockeffectivelythroughsolid-statefermentation.Molecularphylogenyand16SrRNAgenesequenceanalysisdemonstratedthebacterialstrainwasamemberoftheStreptomycesgenus.Toassessitspotentialtoreleasepotassiumfromsilicateminerals,thisstrainwasusedtodegradepotassium-bearingrockpowderbysolid-statefermentation.Afterfermentation,theamountofwater-solubleAl,FeandKofthesubstratewithactiveinoculumwashigherthanthoseofthecontrol,whichhadautoclavedinoculum,andthoseofthefreshsubstrate.Theresultindicatedthatthestrainhadtheabilitytoweatherpotassium-bearingrockandcouldbeusedasaninoculumintheproductionofpotassiumbio-fertilizer,duetoitspotassiumreleaseactivityfromrockandtolerancetohightemperature.

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简介：ThePbconcentrationsofatmosphericaerosolintheChukchiSeaoftheArcticvarywithintherangeof0.167-0.962ng/m3,withanaverageof0.532ng/m3.Theseconcentra-tionvaluesare200timeshigherthanthenaturalbackgroundvaluesofsnowsamplesthere.Cal-culationofthePbenrichmentfactorofaerosolindicatesthattheocean-andcontinent-sourceleadaccountfor9.23%and0.01%,respectively,butindustriallyreleasedPbaccountsformorethan90%oftheatmosphericPb.ThePbisotopiccompositionofaerosolhasrevealedthatthesourcesofleadfromindustrialleadthatcausespollutionincludemainlythewesternpartofNorthAmerica,EastEuropeandtheformerSovietUnion.ThecalculationofthetotalfalloutfluxofPbindicatesthatthemeanvalueofinputfluxintotheChukchiSeais0.02mgm-2a-1,equivalenttothatofsouthernPacificbutslightlylowerthanthatofnorthernIndianSeaandsouthernAtlantic.ItisevidencedthatthePbinputfluxintotheChukchiSeaisfarlowerthanthatofftheBalticSea,theNorthSeaandtheMediterraneanSea.

简介：神农架滑雪场位于国家级自然保护区的边缘地带.运用景观生态学原理和方法,采用3S技术,对滑雪场景观生态体系的结构和功能状况进行评价,通过景观多样性指数、景观聚集度指数等指标量化计算及比较分析,预测了项目建成后对所在区域生态完整性的影响程度及将造成的敏感生态问题.结果表明,评价区自然系统的生物量将减少430.26t,平均净生产力降低为881.55g/m^2·a,项目建设不会改变林地的模地地位,其对生态环境质量仍有较强的调控能力.3S技术结合景观生态学方法将生态环境影响评价由定性评价转向定量预测,为建设项目生态影响评价研究作了有益的探索.

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简介：通过国内外花岗岩体的412对角闪石-黑云母40Ar-39Ar年龄（tAr）与锆石U-Pb年龄（tZr）之间差值ΔtZr-Ar（tZr-tAr）进行的频数统计分析表明：ΔtZr-Ar呈对称正态分布（偏度系数CSK==-0.276,峰度系数CKU=16.52）;ΔtZr-Ar既呈正值又有负值,其众数值为0.70Ma,均值为1.15Ma。采用最小二乘法计算,花岗岩体锆石U-Pb年龄与花岗岩角闪石-黑云母40Ar-39Ar年龄拟合出相关系数很高（R=0.996）,回归系数接近l的线性回归方程（tAr=1.00453×tZr-1.932）。这些统计特征表明花岗岩角闪石-黑云母40Ar-39Ar定年测定结果与锆石U-Pb定年测定结果在允许的误差范围内是一致的,不存在花岗岩锆石U-Pb年龄〉角闪石40Ar-39Ar年龄〉黑云母40Ar-39Ar年龄的规律。结合Dodson＇s矿物封闭温度计算公式中存在问题的剖析,本文得出结论,按Dodson＇s公式计算得出的花岗岩矿物40Ar-39Ar封闭温度不能代表从花岗岩浆晶出造岩矿物40Ar-39Ar体系的封闭温度。